Apparatus for coating hollow glassware



June 1, 1954 R. A. KUEBLER APPARATUS FOR COATING HOLLOW GLASSWARE FiledJune 29, 1950 i1llblll IIIIIIIIIIIIIIIIIIIIYIIIII Wm m-Iil Patented June1, 1954 APPARATUS FOR COATING HOLLOW GLASSWAR-E Robert A. Kuebler,University Heights, Ohio, assignor to General Electric Company, acorporation of New York Application June 29, 1950, Serial No. 171,186

1 Claim.

My invention relates to apparatus for depositing particles of a fume ofa radiation-modifying material upon the inner surface of hollowglassware. More particularly, my invention relates to apparatus forcreating extremely fine particles of radiation-modifying material andfor effecting the immediate deposition thereof upon the inner surface ofa hollow glass article such as a lamp bulb. The invention has particularutility in the formation of a fume of light-diffusing particles and thedeposition of said particles in a uniform coating over the interiorsurface of a lamp bulb as broadly disclosed and claimed in patentapplication serial No. 878, Marvin Pipkin, filed January 7, 1948, nowPatent No. 2,545,896 and assigned to the same assignee as thisapplication.

It has been shown heretofore that extremely fine particles of a suitablecharacter to form an almost perfect diffusion material can be created byburning a combustible silicon compound such as ethyl silicate. Suchparticles can be caused to deposit upon an article directly afterformation and are sufficiently adherent to remain fixed to said articleduring certain uses thereof. The particles can, for instance, bedeposited upon the inner surface of an incandescent lamp bulb and willremain in place thereon without further treatment during the operationsof making the lamp and during the period of use thereof.

One object of my invention is to provide apparatus for efiectivelyburning a combustible compound capable of producing a product ofextremely fine particle size.

Another object of my invention is to provide apparatus for producing, byburning, a fume of particles of extremely small size within hollowglassware without injury thereto and in a. manner effecting a desireddistribution of the particles over the interior surface of theglassware.

Another object of my invention is to provide a burner and associatedapparatus for the effective production and distribution of extremelysmall particles upon the interior surface of hollow articles, whichburner and associated apparatus are adapted to extended periods ofoperation by remaining as free as possible of deposited particles and bybeing as completely sealed as possible from said particles. To this end,the burner is constructed so as to throw the particles outward therefromand so as to be readily brushed free of extraneous particles. Theassociated apparatus is subject to the collection of a much greaterdeposit of particles and is provided with means for automaticallyretaining its efiectiveness by cleaning the deposit therefrom.

And still another object of my invention is to provide a burner foreffectively producing a radiation-modifying product within hollowglassware from fluid materials combining under certain conditions a veryvolatile and explosive mixture which burner is particularly adapted tocontrol the mixing and combustion of said fluid materials and which ispartiuclarly adapted to prevent the accidental mixing and possibleexplosion thereof.

A preferred embodiment of my invention provides apparatus for directinga relatively restricted flow of a gaseous combustible material, having asuitable radiation-modifying product of combustion, and a gaseouscombustion-supporting material in a manner to support a continuousburning and to develop a substantially uniform outward spread of fumecomprised of particles of the product. The apparatus is also preferablyadapted to convert the combustible material from a liquid to a gaseousstate by the introduction of heat thereinto and, by discharging saidcombustible material at a lower elevation than the combustion-supportingmaterial, preventing the accidental overflow of the liquid combustiblematerial into the portions of the apparatus containing saidcombustion-supportmaterial and the development of explosive mixtures inthese portions. Apparatus is also provided for holding the hollowglassware and the source of the radiation-modifying material atoperative relation and for effecting a suitable relative movementthereof to control the deposition of said material over the surface ofthe glassware. Apparatus of the above type produces an excess of theradiation-modifying material which is prevented from depositing upon andinterfering with the operation of the apparatus by the particular designthereof and by suitable shields and self-cleaning means incorporatedtherein.

Still other objects and features of my invention will appear from thefollowing detailed description and from the drawing.

In the drawing, Fig. 1 is a vertical section through a burner fordeveloping a source of lightmodifying particles, a holder for supportinga glass bulb in operative relation to the burner, and apparatus foreffecting the operation of the burner and holder and for eifectingrelative motion therebetween; and Fig. 2 is a perspective view on alarger scale of the burner with certain internal passages thereinindicated in dot-dash lines.

The apparatus shown in the drawing provides for the deposition of alight-diffusing material directly on the inner surface of a vitreousbulb l for an electric incandescent lamp immediately upon the formationof said light-diffusing material in the flame of the burner 2. Thisparticularly effective manner of producing and depositing alight-diffusing material corresponds generally to that disclosed in theaforesaid United States patent application of Marvin Pipkin and providesfor the ready application of a highly eiflcient light-diffusing materialonto the bulb surface in a particularly satisfactory manner.Light-diffusing material applied to a bulb in the prescribed manner isretained by the bulb surface without benefit of a binder.

The bulb l rests in an inverted position on the upstanding collar 3 ofthe holder 4 surrounding the inner and outer support tubes 5 and B forthe burner 2 and is aligned longitudinally with the vertically extendingburner 2. The cycle of operation having to do with bulb :l is initiatedwith the burner 2 at a position immediately above the locating flange orshield on the top edge of collar 3. The bulb l is properly positionedwithin the apparatus by the engagement of the flange I with the openneck thereof and the seating of the outwardly flared end portion .8 ofsaid neck upon the correspondingly flared portion of the collar 3 and isaccordingly aligned and "fixed at an elevation determined by thecooperative functions of said flange 'l and said flared ,portions 8. Therelative position of the bulb I within the apparatus-is determined bythe holder 4 which is located upon the platform 9 carried by the supportcolumns l0l-!] on the main body H .of saidiholder L During the entirecycle of operation, a relative rotative motion occurs between the bulb iand the burner 2 in that the holder 4 is rotated through a belt !2engaging a sheave [3 on the lower end of the main body 1! thereof whichextends through .and is supported by the bracket M. .A source of energy,not shown, moves the belt 12 at a sufficiently rapid speed to cause amoderate rate of rotation'i-n the bulb '-'l whereby a sufficiently rapidrelative movement of the bulbsurface and the burner :2 occurs toneutralize the eifect of any nonuniformdistribution of thelight-diffusing material about said burner '2. Support for the apparatusis provided in the bracket M which can be in the form of a stationarytable or a turret which is indexed to carry the burner to bulb-loadingand other work stations in turn.

The light-diffusing material deposited upon the interior surface of thebulb l is the product of a controlled burning of ethyl silicate vaporsin the presence of oxygen and air and first appears in the apparatus inthe form of a fume thrown off from the flames 45 over the upper end ofsaid burner 2. Heat absorbed by the burner 2 from the flames 15 causesliquid ethyl silicate located within a relatively large central well itto boil off as a vapor which burns over the upper end thereof. However,comparatively little of the ethyl silicate vapors burn'close to theouter surface of the burner 2 as a series of three outlets l1, l8, and19 on diametrically opposite sides ofthe central well [6 direct streamsof oxygen from the end surface of the burner 2 and the majority of thefree ethyl silicate vapors .is sucked into and directed away from theburner 2 by these streams. The three outlets H, .18, and IQ of eachgroup extend from oblique end faces 2ll-29 on the burner 2 at oppositesides of a relatively deep transverse channel 2| thereacross and areaccordingly directed across the axis of said burner 2. Each group ofoutlets l1, l8, and [9 are also offset oppositely from the center of theburner 2 and are inclined oppositely to the faces 2U20 so that the gasstreams discharged thereby are directed over different end portions ofsaid burner 2 and passwithout interference from each other toward theopposite bulb wall.

In other words, all the passages l1, l8, l9 in a given one of the twogroups are inclined in the same general direction with respect to thevertical axis of the tubes 5, 6 and head 2, and each :group of passageshave their axes inclined toward a vertical plane extending through thesaid vertical axis and through the axis of the channel 2|; the twogroups of passages l1, l8, l9 also have their respective axes inclinedin opposite directions with respect to a second vertical plane extendingthrough said vertical axis normal to the first-mentioned plane, and theprojected axes of respective groups of passages extend across oppositesides of the head 2 without intersecting at any point whereby the twogroups project distinct non-intersecting flames which cross .over abovethe said head.

The manner of directing the flames 15 across the :end of the burner 2gives a swirling motion thereto .and keeps the higher temperature zoneclose in around the burner 2 so as to :allow the use thereof within therelatively confining neck portion of the bulb 1 without causing saidneck to be heated to .an extent that it cracks or is injured. Theoutlets IT in opposite halves of the burner 2 .are at somewhat greaterinclination to the burner faces 20-20 than the other outlets 1.8 and L9to cause the outer fringe of the gas discharge therefrom to pass eachother without interference and together with said outlets 1-8 and i9discharge sufficient oxygen to cause separate streams 22 of concentratedf-ume to develo beyond the flames l5. These streams 22 of fume wipe theneck of the bulb I when the burner2 is located adjacent the top of theloeating flange l and are the source of the majority of thelight-diffusiI-ig material deposited upon saidneckportion.

The burner 2 is, at all times during the operation of the apparatus, atan elevation determined by the vertical position of the support meanscomprised of the outer tube -6 and a further extent thereof in the tub23 which passes down through the main body H of the holder 4 tooperating means located below the support bracket 1 4. Overlappingportions of the outer support tube '6 and the tube 23 are fastenedtogether by a screw 24 which also holds the inner support tube 5 inplace through engagement with a depression in the side wall thereof. Theburner support means includes a sleeve 25 around the tube '23 and isretained by the operating means through engagement with the oxygenconnection block 26 which is clamped 'to the lower end of said tube 23.

A second connection block 21 fastened to the bottom surface ofconnection block 26 prov-idesthe means :of supplying ethyl silicate tothe bottom end of the inner support tube 5.

The cycle of operation is initiated with the burner 2 located directlyabove the top edge of the locating flange "l as, at that time, the lever28 of the operating means is then at a lowered position in which theroller .29 thereon rides on the low portion 30 of the :camBl :and holdsthe oxygen connection block 2th to which it is attached by link 32 andthe split :collar 33, and the burner assembly at a correspondingly lowerposition. The burner 2 is not allowed to remain at this position afterthe start of the cycle because of the relatively restricted bulb area tobe coated with the light-diifusing material and is gradually raised tothe position shown by rotation of other higher portions 34 and of thecam 3i into 13051- tion below the roller 29. The rate of movement is toa considerable extent determined by the bulb area to be covered by thelight-diffusing material at any particular moment; however, said ratemust also be less when the burner 2 passes into the upper portion of thebulb as the concentrated streams 22 of the fume do not then wipe thesurface thereof and relatively more time must be allowed for saidmaterial to deposit fro-m the slower moving fume. The considerablygreater area of the upper portion of the bulb l increases the amount oflight-diffusion material required in the upper portion 0.? the movementof the burner 2 and said burner 2 is caused to oscillate up and downthrough a short stroke by the advance of a hollow 36 in the cam 3i intoengagement with the roller 29 to provide said additional material. Thefume within the bulb 2 takes both a vertical curling motion and aspiralling motion because of the form of the bulb I and the particulardirection of the oxygen discharge from the burner 2. Accordingly, allportions of said fume repeatedly wipe or paint the inner sur-- face ofsaid bulb i and produce thereon as uniform a coating of light-diffusingmaterial as possible. The end of the cycle of operation is reachedfollowing a gradual lowering movement of the burner 2 during which theconcentrated fume streams 22 again impinge upon the bulb neck anddeposit a second application of lightdifiusing material directlythereto.

The rates of burning of the ethyl silicate and flow of oxygen are bothpreferably controlled through adjustments of the sources of supply whichare coupled to the connection blocks 27 and 26, respectively, by thepipes 31 and 33, respectively. The flow of ethyl silicate, for instance,is restricted to an amount required to produce the specific coatingrequirements of the bulb I and accordingly is such as to allow thatamount of ethyl silicate to rise to the not top of the burner 2. Theethyl silicate flows from the end of the pipe 37 to a chamber in thecenter of the connection block 27 and from there passes directly up thehollow center of the inner support tube 5 to the well in the centerburner 2. Leakage of the ethyl silicate, which under certain conditionsis explosive, is prevented by the packing rings 33 and 4B which arelocated between the connection block 2'! and the support tube 5 on onehand and between said connection block 2'! and the clean-out plug 4! onthe other hand. However, should some leakage occur between theconnection blocks 26 and 21, it will be dissipated in the open air sincevent grooves 42 between the abutted faces thereof allow it to escape.

Obviously, different operative conditions occur when the apparatus isinitially placed in operation at the start of a day since the burner 2is not then at the elevated temperature it maintains during normaloperation. Accordingly, the controls must be adjusted so that less ethylsilicate passes to the burner 2 during the warmingup period to preventliquid ethyl silicate from flowing out the top of the burner 2. Shouldthe liquid ethyl silicate be fed to the burner 2 at such a rate that itflows out the end of the well I6, no damage can result as it will drainaway from well I6 through the channel 2| and will not mix with theoxygen.

It is imperative that the outlets II, I8, and I9 be at a higherelevation than the well I6 to prevent liquid ethyl silicate from flowingin and mixing with the oxygen therein as such a mixture is violentlyexplosive. The oxygen introduced into the apparatus through the pipe 38enters a chamber in the connection block 26 about the inner support tube5 and flows upward through the lower end of the tube 23 and thencethrough the outer support tube 6 to a ring-shaped opening 43 in theburner 2, the lower terminus for the outlets I1, I8, and I9. Althoughthe rate of flow of the oxygen is less critical than that of the ethylsilicate, it must be controlled so that a desired character of silica isformed and so that the extent of the flames I5 and the fume streams 22will not injure the bulb I and still coat it properly. A deficiency ofoxygen is to be avoided since it produces a dense black and streakedcoating and permits a considerable deposit of silica to quickly collecton the burner 2 preventing its satisfactory operation. Some deposit doescollect upon the burner 2 in normal usage, and it is desirable for saidburner 2 to be cleaned with a wire brush at intervals. The design of theburner 2 is such as to collect a minimum amount of fume and such as tobe readily cleaned by a brush. Leakage of oxygen from the connectionblock 26 is prevented by the packing ring 44 between it and the tube 23and by the packing ring 45 between it and the inner support ring 5.

During the normal operation of the apparatus when a bulb I is in placeover the burner 2, a comparatively slow circulation of air and fumeoccurs from the bulb I through the vent 46 provided between the supportcollar 3 for said bulb I and the outer support tube 6. This passage ofthe fume through the vent 46 causes a certain amount of the silica todeposit upon the surfaces of the collar 3 where it could possibly blockthe free circulation of gases from the bulb I if allowed to build up toany extent. However, scraper 47 at one point on the support tube 6extends into the vent 46 and sweeps the deposit from the full length ofthe collar 3 in the course of the rotative motion of said collar 3 andthe vertical motion of the support tube 6 in each cycle of operation.The excess silica dislodged from the vent 4t and the fume passingtherethrough is thrown clear of the apparatus by the air currentsestablished by the vane 48 on the lower end of the support tube 6. Therelative rotation of the collar 3 and the other parts of the holder 4also creates a mild suction within the vent 46 which assists inwithdrawing the fume therethrough and scrapes the deposit of silica thatfinally collects on the parts within the adjacent area after extendedoperating periods. A shield 49 and the seal provided by the bellows 50,which rotates with the holder 4 and the sleeve 25, prevent the silicafrom depositing upon the outer surface of said sleeve 25 and accordinglyinterfering with theslipping of the said sleeve 25 in the main body I3of the holder 4 during the vertical movements thereof.

Although a preferred embodiment of my invention is disclosed, it will beunderstood that the invention, as defined by the claim, can be widelymodified within the spirit and scope thereof and is not limited tospecific construction and arrangement of parts shown.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

canvases In apparatus for :coating the interior surfaces of hollowbodies, a liquid fuel burner comprising wen'tically arranged concentricinner and :outer tubes, .a burner :head'mounted on the upper ends of.said tubes and havingan axial vertical aperture itherethrough alignedwith the bore of said inner tube and also having an annular portionconnected at its periphery "to said outer tube, said head having .achannel extending diametrica-lly across the upper face thereof through:said aperture, a group :of outlet passages in said annular portion ofthe head at each side of said channel, .said passages communicating atone end with the annular space between said tubes and terminating inorifices at the top of said head above the bottom of said channel, allthe passages in a given group being inclined in the same generaldirection with respect to the vertical axis of said tubes and head, eachgroup of passages having their axes inclined toward a vertical planeextending through said vertical axis and through the axis of saidchannel, the two groupsof passages also having their respective axesinclined in opposite directions with respect to a secondvertical planeextendingthrough said vertical axis normal to the first-mentioned planeand the proj ectedaxes of respective groups of passages "extendingacross opposite sides =0! said head without intersecting at any pointwhereby the two groups project distinct :non intersecting flames whichcross over above said head, means to supply liquid fuel through saidinner tube to the :aperture in said head, and

means *to supply a combustion-supporting gas through the annular spacebetween said tubes to said passages.

References Cited in the file of this patent UNITED STA'IZES

